Funding for widespread Wi-Fi and mobile access on trains is expected to be among George Osborne's budget giveaways this week.

Passengers who prefer quiet carriages will have to grit their teeth – in a boost for national productivity, trains will be transformed into mobile offices for commuters who want to catch up on work.

Of the 25 rail franchise operators, 12 still do not have Wi-Fi on board, according to the Association of Train Operating Companies website. The Heathrow Express offers it free to all passengers, while the Gatwick Express has no service.

The cash will be used to install special equipment on trains, according to industry sources.

A spokeswoman for the Department for Culture, Media and Sport declined to comment.

Mobile phone signals are more likely to bounce off trains than into them, but connections can be improved by fixing antennae to carriage roofs which replicate signals through repeaters in the train.

Virgin Trains installed repeaters on its Voyager services in north Wales and on cross country routes through a contract with Orange, and teamed up with Vodafone in 2008 to bring the technology to its high-speed Pendolino trains between London and Glasgow.

A handful of franchises offer free Wi-Fi to all passengers, but most charge those travelling second class while giving the service free to first-class passengers.

While many people resent having to listen to loud phone calls, internet connections are less disruptive and popular with passengers. National Express registered a threefold increase in passengers along the east coast line after offering free Wi-Fi.

The line was previously operated by Great North Eastern Railway, which charged £4.95 an hour for the service. When National Express removed the charge in January 2008, passenger rates rose from 30,000 to 100,000 for the month, with regulators saying part of the increase was due to free Wi-Fi.

Virgin Media said it wants half of the government's £150m Urban Broadband fund, designed to improve internet infrastructure in cities, to be diverted to skills and training.

BT and Virgin Media are concerned public money could be used to build networks which compete with their own. They have launched legal action against a European commission decision to let Birmingham city council spend £10m from the Urban Broadband fund on installing fibre-optic cables in areas where they already serve customers.

Neil Berkett, chief executive of Virgin Media, has written to the chancellor, George Osborne, suggesting half of the fund be spent improving digital skills for small and medium sized businesses – only two-thirds have a website and just a third sell goods and services online.